1. Field of the Invention
The present invention relates to a substrate processing apparatus and a substrate processing method wherein a to-be-processed object such as a semiconductor wafer and the like is cooled by a cooling process unit in a resist film coating process and the cooled object is transferred to a resist liquid coating unit from the cooling process unit.
2. Description of the Related Art
In a semiconductor device manufacturing process, the photolithography technique is used. In this photolithography technique, a resist coating is applied on the surface of a semiconductor wafer (hereinafter simply referred to “wafer”), and the coated surface is exposed to light and developed to have a predetermined pattern. Since these processes of resist coating, light-exposure, and developing are carried out at about room temperature, a cooling process is carried out such that the temperature of the wafer is set to be substantially room temperature before these processes. Thereafter, a resist film with a predetermined pattern is formed on the wafer, and a film-forming process and an etching process are further performed, so that a circuit with a predetermined pattern is formed.
A series of these resist processes is carried out by a coating and developing process system into which, for example, a resist liquid coating unit, a developing process unit, a cooling process unit, a heating process unit, and a transferring apparatus that transfers the wafer between these units are incorporated.
In the conventional coating and developing process system, the wafer cooling process and the wafer resist liquid coating, light-exposure processing after the cooling process are executed as set forth bellow. Hereinafter, an explanation is given of the resist liquid coating as an example.
In the resist liquid coating process, there are used a resist liquid coating unit for coating a resist liquid onto a wafer, a cooling processing unit for providing a cooling process to a wafer before being subjected to the resist coating, and a transferring apparatus for transferring the wafer between these resist liquid coating unit and cooling process unit. In the resist liquid coating unit, a first wafer is subjected to a resist liquid coating process. In the cooling process unit, a cooling process is provided to a second wafer to be next subjected to the coating process. When the resist liquid coating process to the first wafer is ended, the transferring apparatus unloads the second wafer from the cooling unit, and transfers it to the resist liquid coating unit. Thereafter, the first wafer is unloaded from the resist liquid coating unit, the second wafer is transferred to the resist liquid coating unit, and the replacement of the wafer is ended.
In the light-exposure process, in addition to a light-exposure apparatus, there are used a cooling process unit and a transferring apparatus for transferring the wafer between the light-exposure unit and the cooling process unit similar to the resist liquid coating process. Then, the wafer is subjected to the cooling process before the light-exposure process. After ending the light-exposure process to the wafer in the light-exposure process, a wafer to be next subjected to the light-exposure process is taken out from the cooling process unit.
However, in the aforementioned transferring system, the resist liquid coating process and light-exposure process for each wafer are ended, and the wafer to be next subjected to the resist liquid coating process or light-exposure process is taken out from the cooling process unit and transferred. This causes a problem in which the throughput becomes worse.